#include <stdio.h>
#include <string.h>
 
int main(void){
    char src[6];
    char dest[]="world";
    printf("src 长度：%lu\n",strlen(src));
    printf("dest 长度：%lu\n",strlen(dest));
    strcpy(src,dest);
    //strcpy(dest,src);
    printf("src:%s,长度：%lu\n",src,strlen(src));
    printf("dest:%s,长度：%lu\n",dest,strlen(dest));
    strcat(dest,src);
    printf("src:%s,长度：%lu\n",src,strlen(src));
    printf("dest:%s,长度：%lu\n",dest,strlen(dest));
    return 0;
}